A roller drawing apparatus is described in DE 102 60 025.2. Since the apron covering on the withdrawal cylinder has a running speed approximately 40 times greater than is the case in customary drafting aprons, it is very important that the apron covering is well guided and causes as little friction as possible on the deflection rail. The tensioning force required for the guidance of the apron covering is therefore very low and is advantageously only produced in that the apron covering tends to assume an approximately circular form in the circumferential direction in the unloaded state (DE 103 48 452 A1). Conditioned by this low tension with which the apron covering glides over the deflection roller, fibers collect on the deflection roller during a rather long operation of this apparatus. As a consequence, laps form around the deflection rail that hinder the easy gliding over the deflection rail and generate a higher and higher tension that finally leads to breaking of the deflection rail.
Furthermore, the running properties of the apron covering over the deflection rail are adversely affected in that the yarn insert applied to hinder longitudinal expansion is customarily produced by winding a yarn onto the first inner layer, that is then covered with another layer. As a result, it occurs again and again that, at the high running speed, the apron covering behaves asymmetrically corresponding to the winding and has the tendency to run off to one side. This can be counteracted by positioning edges on the deflection rail. However, the borders of the apron covering are stressed and worn down by running against the edge.